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[Quest]

even if we should not be able to run games like matrix from any place beyond the 137gb limit , wouldn't it be possible to make a partition with the extra space to use it with XBMP -> movies, music, pictures?
i'm pretty shure not even a .wmv movie can exchange the kernel :-)

Quest

[lookformeb]

congrats on holding your ground while standing against the tide in the beginning... i'm anxious to see where this goes

[janson]

QUOTE (oz_paulb @ Aug 28 2003, 01:46 PM)

I just looked at the side of the box for my Maxtor 200GB drive ("System requirements").  It says: QUOTE Drives larger than 137GB require Windows 2000 SP3 or higher, XP SP1 or higher, or ATA/133 PCI card This certainly sounds to me like it'll work on any PC (including Xbox) as long as your software drivers are up to date (have support for LBA-48).  There doesn't seem to be any hardware incompatibilities with 'old' PC's (like Xbox). Maybe the Maxtor drive is unique - if so it looks like I was lucky in my first purchase of a "> 137GB" drive. - Paulb

It's just to add the functionality to use 48bit, however you must have the same support at the hardware. That's what i think.

[dmsdude90]

this rocks keep up the great work    i can't wait till u finish


make a tutorial on this it will change THE WORLD   or just x-s  but that is still great

[janson]

oz_paulb: sorry that i didn't believe in the possibility of doing this. I thought it wouldnt be possible until now. I admit that it was lack of knowledge.

This interested me so i started to read some documentation, the following is my own personal conclusion.

(<ATA 133 = ata33,66 etc.. ATA133> = ata133 and newer..)

<ATA133 uses a 28bit LBA adressing. When windows was developed they allocated 28bit for the LBA adressing, why adress more when it wasn't needed?

ATA133> uses a 48bit LBA adressing. As i wrote before, windows only allocates 28 bit for the LBA adressing as default, that's why you have to use Windows 2000 SP3 or higher, XP SP1 ... It makes windows allocate 48 bits for the LBA adressing.

So, why can't i just update windows and use >137GB on my <ATA133 ? Because the systems with <ATA133, BIOS is set to only allocate 28bit! In newer BIOS for the ATA133> the bios adresses 48bits.

Conclusion: If we could rewrite the bios to allocate 48bit then we should be able to use 137GB> even on 'old systems' running <ATA133. I claim that the limitation is NOT in the hardware, it's in the software.

This is only a theory and i don't know if it works practically or if there's something importatant i've missed,
thank you oz_paulb for working on this, we'll soon have an answear to this.

[archon79]

For you guys wondering about this issue.. here's an interesting read:

http://www.storagereview.com/guide2000/ref.../bios/over.html

BIOS translation (which looks like what paul is doing) seems to be a possible solution to the >137GB drive problem...

BTW, good work regardless of the outcome paul!

This post has been edited by archon79: Aug 28 2003, 04:29 PM

[nyarrgh]

It would be enough for me to add support for an extra partition. Drive G for example?  so that the other partitions remain the same.


Is it possible to access a drive using both LBA24 and LBA48?  It might be okay to add another partition.  Then make all the regular partitions + Drive F available when using LBA24, and all partitions when booting off a bios that supports LBA48.  Sort of like Drive F not being available when booting off the retail bios.

[warbeast]

great work paul  

will it work on  v1.2 v1.3 ?

[oz_paulb]

QUOTE

Conclusion: If we could rewrite the bios to allocate 48bit then we should be able to use 137GB> even on 'old systems' running <ATA133. I claim that the limitation is NOT in the hardware, it's in the software.

This has been my understanding, too.

Shortly before I saw Franz's initial post to this thread stating that it's not possible, I saw the following message on the xbox-linux mailing list:

QUOTE

Franz says that this will not work, because all LBA48 HDs don't support PIO or UDMA2 (which is the highest the Xbox kernel can do) any more, their native mode is UDMA5. Only very few HDs, those with a special compatibility mode will also do slower modes. The Xbox kernel does not have UDMA5, so it will not work.

Now, this is something I could believe - that newer drives are using a new method of DMA'ing in hardware and have stopped doing it 'the old way' (PIO/UDMA2) on the assumption that you've purchased a > 137GB drive, so you must have a newer system.  (I would hope that the packaging would warn about this, though).

Now, I don't know enough about differences between UDMA5 and PIO/UDMA2, but my feeling is that if a drive doesn't support PIO/UDMA2, and the Xbox doesn't support UDMA5, then it just plain won't work - even in LBA28 mode (because I think that this is a lower-level hardware/chipset method of data transfer between the two devices).

If a drive supports PIO/UDMA2 transfers in LBA28 mode, then I don't see why they'd disable that method just because the BIOS software is using the LBA48 commands instead of LBA24 commands - the drive is either hardware-compatible with the PC or it isn't (again, this is my feeling, but I can't say for sure).

So, if a >137GB drive 'works' in a standard Xbox KERNEL (in LBA28 mode - limited to 137GB), then I don't see any reason why it won't work in LBA48 mode with a modified KERNEL.

As I said before, this will be a learning experience for many of us here, and we may find that certain drives are incompatible.  In that case, we'll just need to make a list of 'known good' and 'known bad' drives.  Anyone experimenting with LBA48 in the early stages will risk data corruption - but that's to be expected (I think).

- Paulb

[oz_paulb]

QUOTE (warbeast @ Aug 28 2003, 06:07 PM)

great work paul   will it work on  v1.2 v1.3 ?

It should be possible to patch any KERNEL version to use LBA48, so I don't see why it wouldn't work on 1.2/1.3/1.xx Xbox's.

- Paulb

[oz_paulb]

QUOTE (nyarrgh @ Aug 28 2003, 05:53 PM)

It would be enough for me to add support for an extra partition. Drive G for example?  so that the other partitions remain the same. Is it possible to access a drive using both LBA24 and LBA48?  It might be okay to add another partition.  Then make all the regular partitions + Drive F available when using LBA24, and all partitions when booting off a bios that supports LBA48.  Sort of like Drive F not being available when booting off the retail bios.

It seems like this should work, but some experimentation would be necessary to prove that it's possible.  (Linux is working by having an extra partition above the 137GB line)

- Paulb

[MemphisReins]

I wish I could offer come support but I don't have anywhere near the knowledge this takes to do, so all i can do is offer my congrats and hope that you don't get pissed off by those who doubt you. At the end of the day, things may or may not work, but until you try to find a way around problems, no-one will get anywhere.

Nice one on your work so far and keep it up!      

[KamelRed]

First off, payam go back into the hole you crawled out of. We dont need lamers and flamers in this thread at all.

Secondly, I would like to thank oz_paulb for all his work and giving us hope that the 137gb barrier will be broken.

[oz_paulb]

QUOTE (KamelRed @ Aug 28 2003, 07:00 PM)

Secondly, I would like to thank oz_paulb for all his work and giving us hope that the 137gb barrier will be broken.

Let's remember that it was 'bobmckenzie' who first broke the myth that LBA48 wouldn't work - I'm just taking the info he provided and actually trying it out.

- Paulb

[Xeero]

QUOTE (MemphisReins @ Aug 28 2003, 01:58 PM)

Well, no idea what the dude above me is on about but anyways...

Deleted it.